NASA Ocean Color

ocssw V2022
 #!/usr/bin/env python3
  
  
 __version__ = '2.8.0_2023-08-09'
  
 __dtypes__ = ['','','_DARK','_SOL','_SPCA','_LIN','_LUN','_DIAG','_STAT',
     '_SPEC','','_SNAP-X','_SNAP-I','','_LUN-ST','_RAW']
  
 import numpy as np  
 from l0info_utils import read_packet, read_apid, get_anc_packet_time, is_bad_packet  
  
  
  
 CRC_TABLE = [0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5,
              0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b,
              0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210,
              0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
              0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c,
              0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401,
              0x64e6, 0x74c7, 0x44a4, 0x5485, 0xa56a, 0xb54b,
              0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
              0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6,
              0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738,
              0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 0x48c4, 0x58e5,
              0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
              0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969,
              0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96,
              0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc,
              0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
              0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03,
              0x0c60, 0x1c41, 0xedae, 0xfd8f, 0xcdec, 0xddcd,
              0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6,
              0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
              0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a,
              0x9f59, 0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb,
              0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0x00a1,
              0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
              0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c,
              0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2,
              0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb,
              0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
              0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447,
              0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8,
              0xe75f, 0xf77e, 0xc71d, 0xd73c, 0x26d3, 0x36f2,
              0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
              0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9,
              0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827,
              0x18c0, 0x08e1, 0x3882, 0x28a3, 0xcb7d, 0xdb5c,
              0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
              0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0,
              0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d,
              0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07,
              0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
              0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba,
              0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74,
              0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
              ]
 CRC_LENGTH: int = 4
  
 science_oci_format_header = 0x2bc
 shift_bit = 0xffff
  
  
 def compute_CRC_checksum(data: list, length: int):
     # byte_0 = 0x34  - Logical Address
     # byte_1 = 0x02  - protocol ID
     CRC_BUFFER: list[int] = [ 0x34,0x02] # placing these two bytes in the beggining (SpaceWire Header)
     crcA = 0xFFFF
     crcB = 0xFFFF
     CRC_BUFFER += data[:length]
     size = (length + 2) // 4 
     for i in range(size):
         crcA = CRC_TABLE[((crcA >> 8) ^ CRC_BUFFER[4 * i + 0])
                          & 0xFF] ^ (crcA << 8)
         crcA = crcA & shift_bit
         crcA = CRC_TABLE[((crcA >> 8) ^ CRC_BUFFER[4 * i + 1])
                          & 0xFF] ^ (crcA << 8)
         crcA = crcA & shift_bit
         crcB = CRC_TABLE[((crcB >> 8) ^ CRC_BUFFER[4 * i + 2])
                          & 0xFF] ^ (crcB << 8)
         crcB = crcB & shift_bit
         crcB = CRC_TABLE[((crcB >> 8) ^ CRC_BUFFER[4 * i + 3])
                          & 0xFF] ^ (crcB << 8)
         crcB = crcB & shift_bit
     return (crcA << 16) | crcB
  
  
  
 def get_band_dims(apacket):
  
 # extract aggregation information and compute data dimensions from ancillary packet
  
 #       Arguments
 #
 #       Name    Type            I/O      Description
 #       ----    ----            ---      -----------
 #    apacket    byte(*)         I    Ancillary packet array
 #    ncp    int         O    Number of CCD band pixels
 #    nbb    int         O    Number of blue CCD bands
 #    nrb    int         O    Number of red CCD bands
 #    nsp    int         O    Number of SWIR band pixels
 #    ndc    int         O    Number of CCD dark collect pixels
 #    nds    int         O    Number of SWIR dark collect pixels
 #    btaps    int         O    Blue CCD tap enable flags
 #    rtaps    int         O    Red CCD tap enable flags
 #    itable  struct         O    Spatial aggregation table        
  
 #    orig: Frederick S. Patt, SAIC, 1 August 2018
  
     # Create spatial aggregation table structure
     itable = np.zeros(10, dtype={'names':('dtype', 'iagg', 'lines'),'formats':('i4','i4','i4')})
  
     # Extract spatial aggregation table and compute numbers of pixels
     ioff = 36
     nagg = [1,2,4,8]
     ncp = 0
     nsp = 0
     ndc = 0
     nds = 0
     for i in range(0,10):
         itable['dtype'][i] = apacket[ioff+3]%16
         itable['iagg'][i] = apacket[ioff+2]%4
         itable['lines'][i] = apacket[ioff]*256 + apacket[ioff+1]
         ioff = ioff + 4
         if ((itable['dtype'][i] > 0) and (itable['dtype'][i] <= 12) and (itable['dtype'][i] != 10)):
             if (itable['dtype'][i] == 2):
                 ndc = ndc + itable['lines'][i]/nagg[itable['iagg'][i]] 
                 nds = nds + itable['lines'][i]/8
             ncp = ncp + itable['lines'][i]/nagg[itable['iagg'][i]]
             nsp = nsp + itable['lines'][i]/8
     if (ncp == 0):
         ncp = 1
         nsp = 1
  
     if (ndc == 0):
         ndc = 1
         nds = 1
   
     ioff = ioff + 4
  
     # Extract spectral aggregation and compute numbers of bands
     #  Tap enable flags
     btap = apacket[ioff+2]*256 + apacket[ioff+3] 
     rtap = apacket[ioff]*256 + apacket[ioff+1]
     btaps = np.zeros(16)
     rtaps = np.zeros(16)
     
     #  Tap aggregation factors
     bagg = int.from_bytes(apacket[ioff+8:ioff+12],'big')
     ragg = int.from_bytes(apacket[ioff+4:ioff+8],'big')
     
     baggs = np.zeros(16)
     raggs = np.zeros(16)
     
     #  Compute number of bands for enabled taps
     nbb = 0
     nrb = 0
     ken = 1
     kag = 3
     lag = 1
     
     for i in range(15,-1,-1):
         btaps[i] = np.bitwise_and(btap, ken)/ken
         if (btaps[i]):
             baggs[i] = nagg[int(np.bitwise_and(bagg, kag)/lag)]
             nbb = nbb + 32/baggs[i]
         
         rtaps[i] = np.bitwise_and(rtap, ken)/ken
         if (rtaps[i]):
             raggs[i] = nagg[int(np.bitwise_and(ragg, kag)/lag)]
             nrb = nrb + 32/raggs[i]
         
         ken = ken*2
         kag = kag*4
         lag = lag*4
         
     return ncp,nbb,nrb,nsp,ndc,nds,btaps,rtaps,itable,baggs,raggs
  
 def anc_compare(apacket0,apacket):
  
 # function to compare spatial and spectral data collection parameters
 #  from two OCI ancillary data packets
  
 #        Arguments
 # 
 #        Name        Type    I/O      Description
 #        ----        ----    ---      -----------
 #     apacket0(*)    byte     I    Ancillary packet from first spin
 #     apacket(*)    byte     I    Ancillary packet from next spin
  
 #  Returns 1 (TRUE) if packets agree, 0 if not
     
     anc_compare = 1
     strmsg = ""
     # Compare spatial data collection fields
     ioff = 36
     ilen = 40
     if apacket[ioff:ioff+ilen] != apacket0[ioff:ioff+ilen]:
         c_time = get_anc_packet_time(apacket)
         strmsg += "\nSpatial table change at %s" % c_time.strftime('%Y-%m-%dT%H:%M:%S.%f')
         anc_compare = 0
  
     # Compare spectral data collection fields
     joff = 80
     jlen = 12
     if apacket[joff:joff+jlen] != apacket0[joff:joff+jlen]:
         c_time = get_anc_packet_time(apacket)
         strmsg += "\nSpectral table change at %s" % c_time.strftime('%Y-%m-%dT%H:%M:%S.%f')
         anc_compare = 0
  
     return anc_compare, strmsg
  
 def is_bad_apid(apid,fh):
     if apid == -1:
         return False
     if (apid < 550) or (apid > 749):
         print("Invalid packet header at byte %d."%fh.tell())
         return True
     else:
         return False
  
 def get_oci_data_type(fpacket):
     # To determine the OCI data type from and ancillary packet
     # Returns: dtype (1 - 12) if valid ancillary packet, -1 otherwise
  
     # Check APID
     apid = read_apid(fpacket)
     if (apid != 636): return -1
  
     dtypes = np.zeros(10)-1
     ioff = 36
     for i in range(0,10):
         dtypes[i] = fpacket[ioff+3] % 16
         ioff = ioff + 4
     kd = np.argwhere((dtypes != 2) & (dtypes != 10)) # Exclude dark and no processing types
     dtype = np.max(dtypes[kd])
     
     return int(dtype)
  
  
 def l0info_oci(args, fh, output, bDSB, crcSumCheck):
     # procedure to get start and end times from Level-0 packet files for OCI
     print("Running l0info_oci (version: %s) \n" % __version__)
     
     dtype = -1
     str_stime = ''
     str_etime = ''
     
     status = 0
     if args.verbose:
         print("Reading OCI science data file.")
         
     bSPW = False
     lpoint = 0
     if bDSB:
         # chead = fh.read(64)
         lpoint = 64
         bSPW = True
     fh.seek(lpoint)
     
     # Get first ancillary packet
     apid = 0
     packetLength = 8
     if crcSumCheck:
         print("CRC checksum will be perfomed for each science packet")
     while (apid != 636) and (packetLength > 7):
         try:
             fpacket, packetLength = read_packet(fh, bSPW)
             apid = read_apid(fpacket)
             if is_bad_apid(apid,fh):  return 104
  
             # check CRC sum
             if fpacket and crcSumCheck:
                 phead_format = int.from_bytes(fpacket[:2], "big")
                 if  phead_format == science_oci_format_header:
                     dataCompute = list(fpacket[0:-CRC_LENGTH])
                     crcCalcs = compute_CRC_checksum(dataCompute, len(dataCompute))
                     crcExpected = int.from_bytes(fpacket[-CRC_LENGTH:], "big")
                     if crcExpected != crcCalcs:
                         print(f"Error : CRC checksum failed! Expected {hex(crcExpected)}, calculated {hex(crcCalcs)} for packet with apid {apid}")
                         return 131
         except:            
             return 103
     if is_bad_packet(packetLength,fh):  return 104
     if fpacket:
         print("CRC check finished.")
         
     # If no ancillary packets, rewind and get times from HKT packets
     if fpacket is None: 
         print('No stored science packets found in file.')
         status = 110
         
         fh.seek(lpoint)
         apid = 0
         packetLength = 8
         ccsec = 0
         firstraw = 0
         # while ((apid < 550) or (apid > 750) or (apid == 558)) and (packetLength > 8):
         while (ccsec < 1900000000) and (packetLength>7):
             fpacket, packetLength = read_packet(fh, bSPW)
             if fpacket:
                 apid = read_apid(fpacket)
             else:
                 continue
             ccsec = int.from_bytes(fpacket[6:10],'big')
         # if is_bad_packet(packetLength,fh):  return 104       
         if fpacket:
             mpacket = fpacket
             try:
                 stime = get_anc_packet_time(mpacket[6:12],0,'msec')
                 str_stime = stime.strftime('%Y-%m-%dT%H:%M:%S.%f')
                 # print("start_time=%s" % str_stime)
             except:
                 return 120
  
             while fpacket and (packetLength>7):
                 fpacket, packetLength = read_packet(fh, bSPW)
                 if fpacket:
                     apid = read_apid(fpacket)
                 else:
                     continue
                     
                 # Check for raw mode
                 if (apid == 705) and (not firstraw):
                     dtype = 15  # '_RAW'
                     firstraw = 1
                 
                 if (apid >= 550) and (apid < 750) and (apid!=705):  mpacket = fpacket
             
             if is_bad_packet(packetLength,fh):  return 104
             print("start_time=%s" % str_stime)
             etime = get_anc_packet_time(mpacket[6:12],0,'msec')
         else:
             if output:
                 output.write("datatype=OCI\n")
             print("No packets with valid time tags in file.")
             return status
     
     else:
         # Get data type
         dtype = get_oci_data_type(fpacket)
         if (dtype<1) or (dtype>12):
             print("Invalid data type %d."%dtype)
             return 104
                     
         # Get start time
         try:
             stime = get_anc_packet_time(fpacket,28,'usec')
             str_stime = stime.strftime('%Y-%m-%dT%H:%M:%S.%f')
             print("start_time=%s" % str_stime)
             epacket = fpacket
             etime = get_anc_packet_time(epacket,28,'usec')
         except:
             return 120        
         
         # Read to end of file
         apacket = fpacket
         acomp = 0
         nagg = np.array([1,2,4,8])
         spnp = int.from_bytes(apacket[24:28],'big')
         
         while fpacket:
             etime = get_anc_packet_time(apacket,28,'usec')
             if args.verbose:
                 # spnum = swap_endian(long(apacket(24:27),0))
                 spnum = int.from_bytes(apacket[24:28],'big')
                 tmpstr = ""
                 if ((spnum-spnp) > 10):
                     tmpstr += "\nSpin number gap: %d, %d" % (spnp, spnum)
                 spnp = spnum
                 if (not acomp):
                     tmpstr += "\n\nInstrument configuration change at spin %d, %s" % (spnum,etime)
                     ncp,nbb,nrb,nsp,ndc,nds,btaps,rtaps,itable,baggs,raggs = get_band_dims(apacket)
                     iz = np.where((itable['dtype'] != 0) & (itable['dtype'] != 10))[0]
                     tmpstr += "\nData Type       %s" % str(itable['dtype'][iz])
                     iagg = nagg[itable['iagg'][iz]]
                     tmpstr += "\nNumber of pixels %s" % str(itable['lines'][iz]/iagg)
                     tmpstr += "\nAggregation     %s" % str(iagg)
                     tmpstr += "\nBlue bands: %d   Red bands: %d" %(nbb, nrb)
                     tmpstr += "\nBlue aggregation per tap: %s" % str(baggs)
                     tmpstr += "\nRed aggregation per tap: %s\n" % str(raggs)
                     print(tmpstr)
                     
                     apacket = fpacket
                     
             apid = 0
             while (apid != 636) and (packetLength>0):
                 fpacket, packetLength = read_packet(fh, bSPW)     
                 apid = read_apid(fpacket)
                 if is_bad_apid(apid,fh):  return 104
             
             if is_bad_packet(packetLength,fh):  return 104
             if fpacket:  epacket = fpacket
         
         try:
             etime = get_anc_packet_time(epacket,28,'usec')
         except:
             return 120
     
     str_etime = etime.strftime('%Y-%m-%dT%H:%M:%S.%f')
     print("stop_time=%s" % str_etime)
     
     datatype_name = ''
     if dtype > 0:
         try:
             datatype_name = 'OCI' + __dtypes__[dtype]
             if datatype_name=="OCI_LUN-ST":
                 print("Unexpected datatype [%s] is detected." % datatype_name)
                 status = 130
         except:
             print("OCI data type name reading error.")
             status = 130
     
     if datatype_name=='':
         datatype_name = 'OCI'
     
     print("datatype=%s" % datatype_name)
     if output:
         output.write("datatype=%s\n" % datatype_name)
         if str_stime!='':
             output.write("start_time=%s\n" % str_stime)
         if str_etime!='':
             output.write("stop_time=%s\n" % str_etime)
     
     return status